Installing a mod can be done through either EpicRow or either on the initial game. You can chose which method you want to pick.
If you want to install your mods just for EpicRow I recommend you to use our panel for that. You can read viewtopic.php?f=22&t=2960 on how to do that.
If you want to install mods on your game you would have to install them through a modding tool.
A tutorial on how to do that can be found here: